Diff lock issue

Post by **v-lux** » 24 Feb 2010, 19:24

Ive got an ongoing diff lock problem that i've still not found the solution for. Wondering if anyone has got some fresh perspectives on it.

Rear diff lock is very stubborn to engage, sometimes does, but most of the time it doesnt.
Front one works every time.

Ive made sure the shaft is moving freely in the box, no problem there, engages and disengages freely.
Ive checked that i'm getting vacuum at the reservoir by removing pipes either side of the non-return valve, seems ok.
Blown the return valve out with WD40 just to make sure it wasn't sticking, seems fine.
Checked i'm getting vacuum at the lever end, all seems fine.
Checked the movement of the actuator, it moves in and out, but seems quite slow. (sure i remember them 'popping' in and out...? not gradually moving??)

It's this slow movement and lack of engagement that led me to think it must be low vacuum, but i'm damned if i can find the leak, i just don't know anymore..

Can anyone point out something i might've missed, or another good place to look, its driving me nuts and i really don't like the thought of replacing all the piping.

Post by **v-lux** » 24 Feb 2010, 19:29

Oh, i also tested the actuator by blowing into it and covering the opposite hole (both sides) to see if the diaphragm had a leak, no detectable leak however...

Post by **toomanytoys** » 24 Feb 2010, 19:31

Maybe the actuator is fubarred........ ie diaphragm leaking.. or whatever the pin slides in and out of in the actuator (not seen inside one) is damaged/cruded up

If you have good vac and no leaks and the mech side is free, then it must be the actuator..

could swap the front one to the back to see if it improves...

Post by **axeman** » 24 Feb 2010, 19:32

it may be worth cheaking that that the non return valve is working freely, its located just before the vacume storage thingy (the 3 ball thing), mine was seized and sort of only letting the vacume through some of the time, a quick blast with the air gun (compresser) sorted it out.

got to be worth a try.

neil

Post by **toomanytoys** » 24 Feb 2010, 19:36

vac line collapsed/colapsing?

Post by **v-lux** » 24 Feb 2010, 20:03

vac line collapsed/colapsing?

Could be... really don't want it to be though. Was looking at the routing of the line and it looks a right pain to replace it.

it may be worth checking that that the non return valve is working freely

I do wonder about this actually, however wouldn't this mean there would be low vacuum to the front actuator as well as the rear..?

Im going to have another REALLY close check of the line from the lever to the actuator as based on the front one operation ok, its the only place i can think of that could be losing vacuum.

Might try swapping the actuators over as you suggest toomanytoys, at least that will rule it out one way or another.

Post by **Russel** » 24 Feb 2010, 20:16

Check the little red boot on the actuator. If this is damaged (leaking a bit ) It will give your symptoms.
Russel

Post by **v-lux** » 24 Feb 2010, 21:08

Ahhhh, will it now!!

That little red boot is split as it happens. I wondered whether that had anything to do with keeping the vacuum in the actuator, but foolishly assumed that it must just be there to keep the shaft clean.

Or have i got the wrong end of the stick,
Is the split boot just getting in the way of the movement or does it do the job of keeping in the vacuum? Just intrigued..?

Post by **Aidan** » 25 Feb 2010, 08:35

orange boot is vital to maintain vacuum on engaged side, they will work without it but if vac level is low then they struggle to engage, maybe you vac pump is a bit weak / What's the brake servo like ?
could just be a leak, the rubber seal on the accumulator often poor, or a rubber joint leaking

Post by **v-lux** » 25 Feb 2010, 09:48

I think the vac pump is ok, there's a good strong suck on the line that comes from it to the non return valve. Never noticed anything odd via the braking either.

I did notice yesterday that the seal going into the vac reservoir looked a bit ropey, so stuck a load of silicon on it as a temporary fix just to try and eliminate it as a cause. Kind of thought that it couldn't be that bad or the front one wouldn't engage, but perhaps the vac is low as you say, would explain why the rear one is struggling!

I dont suppose you can buy those little red boots can you? Seems a real shame to have to buy an entire actuator when its just the boot that's faulty..?

Post by **Aidan** » 25 Feb 2010, 11:29

not seperately available they get salvaged off broken units, I haven't any I doubt Russel has, could try Syncrospares

Post by **MoonlightCustoms** » 26 Feb 2010, 15:00

Russel at Syncro-Nutz wrote:Check the little red boot on the actuator. If this is damaged (leaking a bit ) It will give your symptoms.
Russel

Nice one

Ive been having the same prob wth my rear, thats 2 actuators i need then

Post by **v-lux** » 26 Feb 2010, 15:05

Ive swapped over the actuators today and the rear one is now working perfectly.

Not that i doubted it would be the red boot, but this is absolute proof!

Thanks Russel!!

Post by **Russel** » 26 Feb 2010, 20:33

No problem, always like to help were i can.
Russel

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